What is the giant star in the center of the Milky Way?

According to scientists' speculation, these four galaxies have merged into the largest galaxy ever observed by human beings, and the mass of this galaxy is about 10 galaxies.

Astronomers said that according to this observation, we initially judged that each of these four giant galaxies is at least as big as the Milky Way, and each galaxy contains billions of stars. After the collision, the four galaxies will eventually merge into a single giant galaxy, whose mass is about 10 times that of the Milky Way. This discovery is of great significance for studying the formation process of giant galaxies in the universe.

This latest research result was published in the latest issue of Astrophysics. Kenneth Rines, a member of the research team from the Smithsonian Center for Astrophysics in Harvard, said, "If these four galaxies collide and merge, the new galaxy will be one of the largest galaxies in the universe discovered so far. Most of the galaxies we have found so far are like a sand pile, but each grain of sand in this sand pile is an independent individual. This discovery also provides a new basis for us to study the formation process of huge galaxies in the universe in the future. "

With the help of Spitzer Space Telescope, astronomers observed this galaxy collision during routine measurement of a distant galaxy cluster. This galaxy cluster, numbered CL0958+4702, is about 5 billion light years away from the Earth. Astronomers used the infrared spectrograph installed on the Spitzer Space Telescope to observe that an elliptical cluster of galaxies containing four water droplets emitted a rare fan-shaped plume. Three of these four galaxies are as big as the Milky Way, and the other one is three times as big as the Milky Way. In the process of galaxy collision, billions of older stars are ejected, and half of them will eventually form a new galaxy cluster.

Explaining the process of galaxy collision, Linis said, "Most galaxy mergers we know are usually similar to the collision of compact cars. This time, what we observed was like the violent collision of four excavators, which caused dust everywhere. Galaxy collision is a very common phenomenon in the universe. Our galaxy is destined to collide with Andromeda in 5 billion years. This time, the galaxy collision observed by NASA's Spitzer Space Telescope is different from what we usually see. There doesn't seem to be much gas mixing during the collision. This discovery also confirmed to some extent that giant galaxies are formed by the merger of smaller galaxies. "

Other astronomers involved in this research are Ross Fini from the Italian University of Siena and Enriquez vicini from the Harvard Smithsonian Center for Astrophysics.